The present invention relates generally to the field of tube extracting devices, and more particularly to an improved tube extracting device for removing tubes from different types of structures, such as boilers, condensers, evaporators, and the like.
Tubes in high pressure steam boilers are mechanically expanded to seal against the inside diameter of the tube hole. The tubes are flared or “belled” to prevent them from blowing out in the event that the rolled joint fails.
Because of malfunctions or normal preventive maintenance, it may be necessary to remove one or all of the tubes from the boiler. To replace the tubes, they are typically cut axially and then compressed to allow the tube end to be forcibly withdrawn from the tube hole. The compression of the tube ends is typically done manually by a ball peen hammer and a chisel. This method for compressing a tube end is time consuming, laborious, and often results in damage to the drum sheet and injury to the operator.
Various tools have been suggested for removing tubes by using collapsing gripping devices for engaging the tube and pulling the tube out of the tube hole.
U.S. Pat. No. 6,205,632 to Weeks et al. discloses a bulky boiler tube compression tool which uses rotatable jaws to engage and compress the tube into an inwardly-curled cross section to facilitate removal of the tube from the boiler.
U.S. Pat. No. 4,180,903 to Hannigan, Jr. reveals a hydraulic-driven apparatus having a plurality of arms with moving gripping fingers for engaging and crimping the tube.
These prior art devices have complex and bulky structures comprised of a plurality of moving parts subject to easy breakage and expensive repair.